diff --git a/src/crypto/ripemd160.cpp b/src/crypto/ripemd160.cpp
--- a/src/crypto/ripemd160.cpp
+++ b/src/crypto/ripemd160.cpp
@@ -294,7 +294,7 @@
         ripemd160::Transform(s, buf);
         bufsize = 0;
     }
-    while (end >= data + 64) {
+    while (end - data >= 64) {
         // Process full chunks directly from the source.
         ripemd160::Transform(s, data);
         bytes += 64;
diff --git a/src/crypto/sha1.cpp b/src/crypto/sha1.cpp
--- a/src/crypto/sha1.cpp
+++ b/src/crypto/sha1.cpp
@@ -162,7 +162,7 @@
         sha1::Transform(s, buf);
         bufsize = 0;
     }
-    while (end >= data + 64) {
+    while (end - data >= 64) {
         // Process full chunks directly from the source.
         sha1::Transform(s, data);
         bytes += 64;
diff --git a/src/crypto/sha512.cpp b/src/crypto/sha512.cpp
--- a/src/crypto/sha512.cpp
+++ b/src/crypto/sha512.cpp
@@ -256,7 +256,7 @@
         sha512::Transform(s, buf);
         bufsize = 0;
     }
-    while (end >= data + 128) {
+    while (end - data >= 128) {
         // Process full chunks directly from the source.
         sha512::Transform(s, data);
         data += 128;